title: Wide complex tachycardia in the presence of class I antiarrhythmic agents: a diagnostic challenge.
abstract: We present two patients with paroxysmal atrial fibrillation on class 1C antiarrhythmic drugs without concomitant atrioventricular (AV) nodal blocking agents who developed atrial flutter with 1:1 AV conduction. Their electrocardiogram revealed wide complex tachycardia with rates >200/minute. Atrial flutter with 1:1 conduction in the presence of class IC antiarrhythmic drugs may present a diagnostic challenge. These cases illustrate the importance of coadministering an AV nodal blocking agent with class IC antiarrhythmic agents in patients with atrial fibrillation. The differential diagnosis of wide complex tachycardia in patients taking class IC agents should include atrial flutter with 1:1 AV conduction.
authors.affiliation: Department of Medicine, Cardiovascular Section, University of Oklahoma Health Sciences Center, Oklahoma City, OK.
authors.forename: Bhaskar
authors.initials: B
authors.lastname: Bhardwaj
authors.forename: Ralph
authors.initials: R
authors.lastname: Lazzara
authors.forename: Stavros
authors.initials: S
authors.lastname: Stavrakis
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D001281:Atrial Fibrillation / Q000139:chemically induced / Q000150:complications / Q000175:diagnosis; D001282:Atrial Flutter / Q000139:chemically induced / Q000150:complications / Q000175:diagnosis; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D013610:Tachycardia / Q000139:chemically induced* / Q000150:complications / Q000175:diagnosis*
chemical_list: D000889:Anti-Arrhythmia Agents
keywords: antiarrhythmic agents; atrial flutter; wide complex tachycardia